Lifting-jack.



PATENTED FEB. 6, 1906.

H. M. MARSH. LIE-TING JACK.

APPLICATION FILED 001'. .,'19'05.

UNITED STATES HUGH MARSH, OF CHICAGO, ILLINOIS.

LiFTiNG"dAGK,

Specification of Letters Patent.

Patented Feb. 6, 1906,

Application filed October 4, 1905. Serial No. 281,305]

To 'rtZZ whom it may concern:

it known that I, HUGH- M. lVlARSII, a citizen of the United States, and a resident of Chicago, county of (look, and State of Illinois, have invented certain new and useful improvements in Lifting-Jacks, of which the formed upon one .a jack of the type following is a specification, and which are illustrated in the accompanying drawings, forming a part thereof.

The invention relates to a lifting-jack of that type in which there is provided a liftingbar having a sliding engagement with a suitable standard and having ratchet teeth of its faces with which two pawls-one attached to an actuatingdevcr and the otherpivotally secured to the standard-cooperate for raising and lowering the bar and for supporting it in any desired position. 1

More especially, the invention relates to a jack oi this type in which the movement of the pawls into and out of engagement with the ratchet-teeth of the lifting-bar is controlled by a spring which is flexed during the operation of raising operation of; lowering to alternately move each of the pawls into and out of engagement with the bar as the actuating-lever is oscillated.

The object of the invention is to provide in described reliaole means for controlling the movement of the pawls, the efliciency of which shall not be impaired by the wearing away of the parts.

A detail of the invention provides that one of the )awls shall be thrown into engagement with t e lifting-bar by gravity in case the s ring controlling the movement of the pawls s ould break at any time during the operation.

i The invention consists in the construction 5 part shown in Fig. 4.

and arrangement of parts'to be hereinafter and as illustrated in in which Figure 1 is a side elevation of a liftingjack constructed according to the invention, a portion'of the outer casing being removed to show the internal construction. Fig. 2 is similarto Fig. 1 with the outer casing in lace. Fig. 3 is similar to Fig. 1, but showmg the parts in a different PUSH/1011., Fig. 4 is a central longitudinal section of one of the parts, and Fig. 5 is a rear elevation of the described and claimed The jack comprises a suitable standard 10 to urge both of the pawls I into engagement with the bar and during the l and a lifting-bar 11, both of ordinary construction, the li'fting bar sliding vertically: within the stand ard and having the 'usual ratchet-teeth.iormed upon one of its sides. An actuating-lover 12 is pivoted at 13 to the standard 10, which is extended, as indicated at 14 14, to provide a suitable bearing for the pivot and a housing 15 for other movable parts. Preferably a portion of one side of the standard 10 is made removable to form an openable cover-plate 16 for the housing 15, which will normally be attached byscrewbolts 17 17 andis shown as having been re moved in Figs.,1 and 3. A pawl 18 is pivotally attached to the inner end of the actuat ing-lever 12 for communicating the motlonpn the lever-to the lifting-bar, and a retainingpawl 19 is pivotally attached to the-standard 1Q, preferably some distance below'the pawl As so far described the 'ClBVlCtilS of well knownconstruction, the novel features of the invention residing in the construction and operation of the mechanism for controlling .the movement of the pawls 18 and 19 into and out of engagement with the ratchet-teeth of the lifting-bar 11. For this purpose there is rovided a sprmgrod 20, preferably being ormed in a coil 21 of one or more turns about midway of its length to increase its flexibility and having a sliding engagement with a 'loop 22 23 on each. of the pawls 18 and 19. This spring is adapted to be flexed to control the movement of the pawls by means of an arm which is pivotally attached to the inner end. of the actuating-lever 12 by means of a pin 24, as clearly shown in Fig. 4, and which has a shoulder 25 extending transversely across its end and bearing against the spring. As

shown, the movement of the farther end of the arm is guided. by the 1 'alls of a recess 35,

formed in the wall 01 the standard, to impart a rocking movement to the arm as the actuatlug-lever 12 is oscillated, the arm swinging in the reverse direction from the movement of the lever. Preferably the shoulder 25 is recessed, as indicated at 26, to receive the coil 21.

A movable jaw 27 having a sliding engagement with the arm 24, cooperates with the shoulder 25 for flexing the spring 20 when the device is to be employed for lowering a load. This jaw is controlled by means of a turn-button 28, rotatably secured to the arm 24, as shown at 29, and having an eccentric portion 30, which cooperates with a slotted aperture 31 in the movable jaw 27 to reciprocate it. The movement of the jaw on the arm 24 is guided bya pin 32, projecting into a slot 33, formed in thearm, andby means of flanges 34 34, which engage the side edges of the arm. The turn-button 28 projects through the cover-plate 16, so as to be conveniently accessible'for manually adjusting the'positron of the jaw 27, a slotted aperture 36 in the cover-plate being provided to allowfor the necessary horizontal movement of the turnbutton as the arm 24 is rocked by the actuating-lever.

The operation of the device is as follows: The spring-rod is normally substantially straight, and the shoulder 25, overwhich it is hooked, is preferably so disposed as to flex the spring slightly to the left of a line joining the guide-loops 22 23 as viewed in Fig. 1. When the jack is to be used for raising a load, the movable jaw 27 is thrown back, so that the spring-rod 2O rests freely against the shoulder and continually urges both of the pawls 18 and ,19 into engagement with the ratchet-teeth of the lifting-bar. With the parts in this positionthe actuating-lever 12 may be operated in the ordinary manner'for raising the bar, the rocking of the arm 24 as the lever oscillates causing the s'pring-rT2O to flex more or less, but always in the same direction.

v rward on the arm 24 manually rotating the turn-button 28, the

disposition of the eccentric 30 being such that S shape, as'shown in Fi 3, and the direction be raised without lifting the bar.

of curvature is reversed b the actuating-lever.

- bar, the retaining-pawl 19 being thrown out to permit the bar to descend with the lifting pawl -18 when the latter occupies its highest position, the lifting pawl 18 being thrown out when in its lowest position to permit it to Moreover, the forms assumed by the spring are r such that as-it bears upon one of the pawls to release it it also reacts upon the other pawl to engage it with the ratchet-bar, and, as shown, the parts have been so proportioned that the spring-rod is not curved to exert sufficientg force for releasingone of the pawls until after it has advanced the other pawl, and the lifting-bar is therefore always supported by at If, however, it is desired to use the device for lowering a load, the movable 'aw 27 will be thrown o each movement of en, therefore, this lever reaches the limits 'of its up-and-downpawl pivote r Preferably the pivotal supports for both of the pawls.ar e so disposed that neither of the pawls is ever thrown back of a vertical position, and bothpf them would fall by their ownweight into engagement with the ratchetbar to support it should the spring-rod 20 be broken at any time.-

The vspring-rod 20 is prevented from working longitudinally out of its seat by means of the recess 26, formed in theshoulder v25 of the arm 24, which receives the coil 21, a corresponding recess 39 being formed inthe face of the jaw 27 which cooperates with it to.

completely surround the coil when the lowering position has been assumed.

I claim as my invention 1. In a lifting-jack, in combination, 'a standard, a lever pivoted to the standard, a rack barin sliding engagement with the standard, a pawl carried by the lever, a spring-rod engaging the pawl, and means carried by the lever for engaging the spring to deflect it as the lever makes its stroke.

2. In a lifting jack, in combination, a standard, a lever pivoted to the standard, a rack bar insliding en agementwith the standard, a awl ivote to the standard, a

pawl pivote to t e lever, a spring-rod connecting the pawls, and a spring-deflectorc'arried by the lever:

3. In a lifting-jack, in combination, a

standard, a lever pivoted to the standard, a,

rack-bar in en agement with the standard, a pawl ivote to the standard, a pawl pivoted to tile lever, a spring-rod connecting the pawls, and a spring-deflector piv otally united to thelev'er and engaging the wall of the stand ard.

4. In a lifting-jack, in combination, a

rack bar sliding engagement with the standard, a pawl pivoted to the standard, a pawl pivotedto the lever, a spring-rod connecting thepawls, a spring-deflector pivotally united to the lever and engaging the Wall of the standard, anda movable jaw mounted on the spring-deflector.

- 5. In a lifting ack, in combination, a standard, a lever pivoted to the standard, a

rack-bar in sliding engagement with the standard, a (pawl i'voted to the standard, a

to thelever andin sliding engagement with the. standard, a shoulder'set transversely on thearm, and a movable jaw mounted onthe arm. Y

standard, a lever pivoted to the standard, a

to t clever, a sprin -rod connecting the pawls, an armpivotal y secured '6. In a lifting-jack, in combination, a 4

standard, a lever pivoted to thestandard, a

on the pawls and havin a coil intermediate its ends, and a .spring de ector carried by the lever and recessed to receive the coil.

7. In combination, a ratchet member, two pawls engaging the ratchet member, a springrod connecting the pawls, a pivoted lever for actuatingone of the awls, and a spring-de- V flectorcarried'by the ever.

8. In a lifting-jack, in combination, a

standard, a ratchet-bar reciprocatingin the standard, a hand-lever'pivo-ted to the standard, a pair of pawls engaging the bar, one being ivoted to the standard and the other to the ever, a sprin -rod unitin the awls, an

armpivoted to t e lever an in siding engagement with the standard and having transverse jaws engaging the spring.

9. In a liftingjack, in combination, a standard, a ratchet-bar reciprocating in the standard, a hand-lever pivoted to the stand ard, a pair of pawls-engaging thejbar', one be ing pivoted to the standard and the other to the ever, a sprin -rod unitin the awls; an

arm pivoted to t e lever an in s 'ding engagement with the standard and having a transverse shoulder engaging the spring, a"

jaw slidingly enga gthe arm and an eccentrio mounted on t e arm and (lbntrolling the jaw.

standard, a lever, a springcontrolled 10. In a" lifting 'ack, in combination, a standard, a ratchetar recipro'catingin the standard, a lever,. a spring --actuated pawl,

and automatic means for reversing the sprin action on the awl as the lever-approac es the limits of its stroke.

11..In a li'r'ting- 'ack, in combination, a

standard, a ratohetar reciprocating in thei pivoted on the lever, a spring-controlle retaming-pawl pivoted on the standard, and means carried by the lever for reversing the spring action on the'pawls as the lever reaches ,t e limits of its stroke.

12.111 alifting- 'ack, in combination,a

standard, a ratchet,- ar reciprocating in the standard, a lever, a springcontrolled awl pivoted on the lever, and means carrie by the lever for reversing the sprin action on the awl as the leverreaclies the imits of its stro (e.

13'. In: a liftingjack, in combination, a standard, a ratchet bar reciprooatin iii-the standard, a lever,ra s ring controlle retaining-pawl pivoted'on t e standard, and means earned by the-lever for reversing the spring action on the pawl as the lever re'aehes the limits of itsstroke. t I

. HUGH M. MARSH. Witnesses CHAs. B. GILLSON, E.- M. Km'ronma. 

